Vulcanizing mold for inner tubes and the like



April 26, 1932. P. DE MATTl-A 1,855,753

VULCANIZING MOIQD FOR INNER TUBES AND THE LIKE Original Filed Aug. 29, 1928 2 Sheets-Sheet 1 i\ E Znve 72751 f; amma 7 April 26, 1932. P. DE MATTIA 3 VULCANIZING MOLD FOR INNER TUBES AND THE LIKE Original Filed Aug. 29, 1928 2 Sheets-Sheet 2 INVENTOR. I

BY 1 m Patented Apr. 26, 1932 UNITED. STATES PATENT orr lcla PETER DE MAT'I'IA, or- PASSAIC, NEW JERSEYQASSIGNOR '10 NATIONAL RUBBER MACHINERY COMPANY, A CORPORATION OF omo VULCANIZING- MOLDIOR INNER TUBES AND THE LIKE Original application filed August 29, 1928, Serial No. 302,710. Divided and this application filed June 28,

1930. Serial No. 463,099.

This invention relates to improvements in vulcanizing apparatus, and refers partlcularly to means for supplying air or other inflating pressure fluid to inflatable articles, such as inner tubes and the like, while they are being vulcanized in molds or presses.

I In one method of producing inner tubes, vulcanization is carried out in steam jacketed molds while the tubes are inflated with air or other fluid under pressure. The tubes are provided with valve stems through which they are inflated and deflated, and in connecting these valve stems with the fluid supply conduits, screw-threaded couplings or unions are ordinarily employed. These old types of connectionshave given rise to objections in that they require considerable time in being made and broken, and moreover they frequently result in the uneven curing of the tubes as well as in the slowing up of production. Recent advances in the art have reduced the time necessary for vulcanizing inner tubes, and it has become more imperative than ever that the vulcanizers be capable of quick loading and unloading to avoid the foregoing and other objections.

With this object in view, the present invention provides an air pipe coupling in which a fluid-tight joint will automatically be established between the valve stem and the coupling as the unvulcanized tubeis positioned in the mold cavity. More specifically, the invention contemplates a coupling which is mounted in fixed relation to the mold and which has a socket for receiving the end of the valve stemas the latter is shoved through the customary hole. or aperture formed in the inner wall of the mold cavity. At the bottom of this socket, there is a fluid-conducting member which is engaged by theabutting end of the valve stem, forming a fluidtight joint, and the valve stem is locked in position by a clamping member mounted on the fixed mold section. Preferably, the coupling includes telescopic members which are relatively adjustable to compensate for variations in length of different valve stems.

Another feature of the invention is the provision of air pipe connecting means adapted particularly for use in or with a sectional vulcanizing mold whose parting lines are offset from the central circumferentialplane of the mold, so as to leave intact the inner or base wall which contains the receiving aperture for the valvestem. To this end, the clamping member previously alluded to is formed as a sliding bar arranged in the mold wall and at an angle to the axis of the valve stem receiving aperture. The guideway for this sliding bar intersects said valve stem receiving aperture as well as the mold cavity, and the inner end of the bar is so formed that one portion of it clampingly engages against the valve stem, and another portion fills up the cutaway portion of themold cavity wall. This arrangement is particularly advantageous in that it facilitates insertion of bent valve stems as well as straight ones.

The invention is disclosed in my pending application for Letters Patent for vulcanizing mold for inner tubes and the like, Serial No. 302,710, filed Aug. 29, 1928, of which the present application is a, division; The foregoing and other objects, features,

and advantages of the invention will be fully appreciated from the following description in connection with the accompanyingdrawings, wherein one embodiment of the invention has been shown byway of illustration, andwherein Figure 1 is a vertical longitudinal sectional view through a vulcanizing press equipped with an air pipe connection made in accordance with the invention;

Fig. 2 is-a fragmentary longitudinal sectional view through the apparatus on a larger scale;

Fig. 3 is a top plan view thereof with parts broken away and parts in section;

Fig. 4 is a detail perspective view of the valve stem clamping member; and

Fig. 5 is an inner end view of the coupling and clamping means disconnected from the mold.

Although the invention-is adapted for use in other types of apparatus, it has herein been illustrated specifically as applied to a tube vulcanizing press wherein a pair of opposed moldsections 10 and 11:are respectively attached to platens 12 and 13, hingedly con nected together at 14, the lower platen 12 being supported in fixed position by means of suitable standards 15 and 16, and the upper platen13'beingm0vable toward and from the fixedplaten by means-eta suitablepower mechanism 17, all as more fully described in copending application Serial No. 271,695,. filed April'21, 19281 The meetlngiaces oi the mold'sections 10 and 11 areprovided with 1glrooves which, when the. press. is closed,-,de=. ne a continuous annular mold cavity 18 within which; an inner; tube 'oruthe likeais adapted to be confined for vulcanization.

Heat is supplied by the circulation of steam onother heating medium through jackets or chambers 19 and20%which-isurround -the cavity-18in thenusualmanner, and pressure is applied .to. theiconfined'a ubber tubeby: inflating it through i the novel connecting means taznces. froni, the centralcircumferential plane of the mold.::, In-iother :words, said parting lines intersect :the cavity-r18 circumferentially' insuch a manner as to define a truncated cone;whose sides pass-diagonally through the center of :the lIlQldlICflV-zltY'fiIlCl whose apex isplocatediimithez directionuof the opening InQYement'iofth-e movable section 11: as it. is carried:.upwardlyrbythe platen 186- With thisiarrangement, it:;willi.beobserved that the lower moldsectionlO presents-a side-wall 24 to; engage the; green-1 orv unvulcanized tube tlireuglrout the; ;major--.portion-, of: its: radial extent, 1 and: an overhanging.- inner wall 25" to engage, thei tube.- throughout; its: base zor= the major-portionofintsaxial extent; .The meeting: faces; ofrthe two; mold' sections extend obliquely from the points 22 andc23-Jas indicatedat 261a11d 27; (Fig. 1) and: thence are/offset in planes 28; and 129;; locatediah opposite sides. of, ibut'iparallel; tot-he central: circumferential plane. The-beveled or' inclined portio11s26i EIIKLQZ form: a: tapered bore fit serving to. accurately: register: the mold sections when in closed relation, and thus provide a fiuidetight;jointgto prevent; the formation of rinds or fins orr thez'vulcanized tube, the-fiat or parallel!portionseat28. and 29 being slightly spaced? apart: 'i'toi provide the necessary learance. This; specifictype of: mold: forms the subject: of==cop-ending applicationvserial l l o. 263,623, filed March 22, 1928, to which referencemaybeihad for further. particulars.

Coming 110W toethes. presenti invention; lit Wi l be seemthatathe naiielrconnecting means 21 isiassociated with thelowen 0r ifixed: mold ection 1% andiisiin theznatureaof a socket or the inner side of the mold section 10 as by bolts 34 and provided with a boss 35'having a longitudinal bore 36 in axial alinement with ,a valve stem opening 37., in the mold wall..25.

Thisbore 36'i's of sufiicient diameter to snugly receive one end 38 of an L-shaped fitting or gun 39, the other end-ofwhich is secured to an air supply pipe 40. The gun 39 is adjustable toward and from the mold wallrand is clamped in its adjusted position by a set screw 41, such adjustment being provided in orderto accommodate valve stems of different lengths. The outerend-38 of the air gun is counterboredto provide a socket 42 for the reception oftheend of a valve stem 43, the reduced extremity of which, as best shown in Fig. 2, is adapted to abut against a knife edged annular shoulder 14 on a nipple 45 screwed into the bottom ofthe socket 42. The nipple 45 also has a reduced extremity 46 which is adapted to extend into i the end of the valve stem to uide it to its seat against theshoulder445 an to direct the inflating air into it.

For the purpose of firmly holdingv the valve stem lg during the vulcanizing operation,

novel locking mea-nsare provided as will now 'be'explained. A "locking-bar 50=is slidably arranged in an opening 51 extending diagona-lly'through the mold wall'and intersecting the valve stem opening' 371 The inner end ofthe bar50 (see Fig.4) is formedwith a curved surface 52 adapted to engage the lower side of the-valve stem and another curved surface '53 which'is flush withthe surface of the mol'd cavitywhen' the bar is in its' locking position. The outerend of the bar 50 is pivotally connected at'54 -t0=' a 'lever55', which, in turn, isspivoted at 56 to -the:bracket 331 The lever preferably extends downwardly from the bracket- 33- and is provided, at its lower end, with-a forwardly extending push rod 57 having a pad 58 on its extremity whereby it may be rocked to unlocking positionby ma-nual pressure.

'A tension spring59 acts upon'the' lever 55 7 to normally maintain theb r 50 in its looking position; and thus-the valve stem-will be =.fi1-n1ly. zheld during the vulcanizingoperations.

In 1lSlIlg thlS form of the invention, the

- gun 39-is first adj usted to its proper position to accommodate valve stems of a-certain length, and it is locked in such position by the'sc-rew41'. Then :wliilethe mold is open,

the attendant places: an unvulcanizedtire in the cavity of the fixed-mold section, pushing the valve stem 413 through the opening 37-v and to its seat against the knife-edged sh0ulcler44'iof' the nipple 45; Pressure, which has in themeantime'been applied' to the pad 58 to retract the bar 50, is then released, whereupon the spring 59 draws the lever forwardly to effect the clamping of the valve stem by engagement with the upper end of the bar 50. The closing of the press, inflation of the tube, and subsequent opening of the press may then be carried out either manually or automatically as desired. Thus, the operations of loading and unloading the vulcanizing unit can be very quickly performed because the connections between the valve stem and air supply are automatically made and broken as the tubes are successively inserted and removed. The invention is extremely simple in construction, capable of being economically produced, and constitutes a substantial advance in the art.

The use of the clamping bar 50 in the illustrated embodiment also permits the vulcanization of inner tubes with bent or crooked valve stems. In other words, when the bar 50 is withdrawn in the manner described, it leaves an opening 60 through the mold wall 25 which communicates with a vertical opening or slot 61 also cut through the mold wall, these two openings in conjunction with a slot 62 formed in the upper side of the bracket 33 permitting the insertion of the bent valve stem, and the bar 50, when released, acting to clamp said valve stem in place. In this instance, the old type of air connection may be used for cooperation with the bent valve stem if desired.

Obviously the invention is susceptible of numerous modifications in the details of construction and arrangement of parts, and the right is herein reserved to make such changes as fall within the scope of the appended claims without departing from the spirit of the invention.

Having thus described my invention, what I claim is:

1. In or for a vulcanizing mold having an apertured wall for the reception of an inflation valve stem, means for clamping a valve stem in position in the apertured wall, said means comprising a locking bar slidable'angularly through the mold wall and into engagement with the valve stem, and means for sliding said locking bar to its locking and unlocking positions.

2. In or for a vulcanizing mold having an apertured wall for the reception of an inflation valve stem, means for clamping a valve stem in position in the apertured wall, said means comprising a locking bar slidable angularly through the mold wall and into engagement with the valve stem, a spring acting to normally maintain the bar in its locking position, and means for retracting the bar against the action of said spring.

3. In combination with a vulcanizing mold having a cavity for confining an inflatable article to be vulcanized and an apertured wall for the reception of an inflation valve stem associated with the inflatable article, valve stem clamping means comprising a bar slidable diagonally through the mold wall, the inner end of said bar having a surface for engaging the side of the valve stem and anothersurface which, in the locking position, is continuous with the surface of the mold cavity, and means for sliding said bar to its locking and unlocking positions. I

4. In combination with a vulcanizing mold having a cavity for confining an inflatable article to be vulcanized and an apertured wall for the reception of an inflation valve stem I associated with the inflatable article, valve stem clamping means comprising a bar slidable diagonally through the mold wall, the inner end of said bar having a surface for engaging the side of the valve stem and another surface which, in the locking position, is continuous with the surface of the mold cavity, a lever pivoted to the mold section and connected with the bar whereby rocking movement of the lever will result in sliding the bar to its locking and unlocking positions, and a spring acting on the lever to normally maintain the bar in its locking position. I

5. The combination of a vulcanizing mold having an apertured wall for the reception of an inflation valve stem, and a spring pressed bar slidably mounted in said mold and extending into said aperture for yielding engagement with the valve stem therein.

In testimony whereof, this specification has been duly signed by:

, PETER DE MATTIA. 

